WO2016019491A1 - 一种光伏并网逆变器的保护系统及方法 - Google Patents

一种光伏并网逆变器的保护系统及方法 Download PDF

Info

Publication number
WO2016019491A1
WO2016019491A1 PCT/CN2014/083622 CN2014083622W WO2016019491A1 WO 2016019491 A1 WO2016019491 A1 WO 2016019491A1 CN 2014083622 W CN2014083622 W CN 2014083622W WO 2016019491 A1 WO2016019491 A1 WO 2016019491A1
Authority
WO
WIPO (PCT)
Prior art keywords
inverter
transformer
primary side
controller
photovoltaic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2014/083622
Other languages
English (en)
French (fr)
Inventor
耿后来
徐清清
邢军
杨本和
李浩源
梅晓东
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sungrow Power Supply Co Ltd
Original Assignee
Sungrow Power Supply Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sungrow Power Supply Co Ltd filed Critical Sungrow Power Supply Co Ltd
Priority to CA2953834A priority Critical patent/CA2953834C/en
Priority to US15/324,101 priority patent/US20170207693A1/en
Priority to CN201480079927.7A priority patent/CN106463968B/zh
Priority to PCT/CN2014/083622 priority patent/WO2016019491A1/zh
Publication of WO2016019491A1 publication Critical patent/WO2016019491A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/38—Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel
    • H02J3/381—Dispersed generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/122—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. DC/AC converters
    • H02H7/1227—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. DC/AC converters responsive to abnormalities in the output circuit, e.g. short circuit
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/42—Conversion of DC power input into AC power output without possibility of reversal
    • H02M7/44—Conversion of DC power input into AC power output without possibility of reversal by static converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2101/00—Supply or distribution of decentralised, dispersed or local electric power generation
    • H02J2101/20—Dispersed power generation using renewable energy sources
    • H02J2101/22—Solar energy
    • H02J2101/24—Photovoltaics
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

Definitions

  • the present invention relates to the field of photovoltaic power generation technologies, and in particular, to a protection system and method for a photovoltaic grid-connected inverter.
  • a transformer is connected between the inverter and the power grid.
  • the photovoltaic grid-connected system with transformer is introduced below with reference to the accompanying drawings.
  • FIG. 1 the figure is a schematic diagram of a photovoltaic grid-connected system with a transformer in the prior art.
  • the PV shown in Figure 1 is a photovoltaic panel, and the PV output is direct current. After inverter 100 is inverted into alternating current, the alternating current is isolated by transformer T to deliver energy to the grid.
  • the side where the transformer T is connected to the grid is defined as the primary side (A, B, C), and the side of the transformer T connected to the inverter 100 is the secondary side (a, b, c).
  • the three sides of the primary side (A, B, C) of the transformer T are connected in a star shape, and the neutral point N is connected to the ground.
  • the primary side of the transformer T that is, any one of the three phases of the three-phase failure occurs on the grid side
  • the voltage, frequency, and phase of the secondary side of the transformer T are almost the same as those in the normal state. That is, when the primary side of the transformer T fails, the secondary side of the transformer T does not sense a fault, and the inverter continues to operate.
  • an overcurrent problem occurs on the transformer, which eventually leads to damage to the transformer.
  • the invention provides a protection system and a method for a photovoltaic grid-connected inverter, which can protect a photovoltaic grid-connected inverter and a transformer in time when a fault occurs on the grid side.
  • the embodiment provides a protection system for a photovoltaic grid-connected inverter, comprising: a detecting device, a photovoltaic panel, an inverter, a transformer, and an inverter controller; An output end of the photovoltaic panel is connected to an input end of the inverter, the inverter inverts direct current outputted by the photovoltaic panel into alternating current to the transformer, and a secondary side of the transformer is connected to the inverter Output, the primary side of the transformer is connected to the power grid;
  • the primary side of the transformer is a star connection, and the neutral point of the primary side is connected to the earth;
  • the detecting device is connected between the primary side of the transformer and the power grid;
  • the detecting device is configured to detect whether a single-phase open circuit fault occurs on the primary side of the transformer; when detecting a single-phase open circuit fault on the primary side of the transformer, send a fault signal to the inverter controller ;
  • the inverter controller is configured to control the inverter to stop according to the fault signal.
  • the detecting device detects a single-phase open-circuit fault on the primary side of the transformer, which is:
  • Whether the single-phase open circuit fault occurs on the primary side is detected by detecting the three-phase current imbalance on the primary side of the transformer;
  • a single-phase open-circuit fault is detected on the primary side by detecting the current flowing through the N-line on the primary side of the transformer.
  • each inverter is respectively connected to respective corresponding photovoltaic panels; the output ends of all the inverters are connected to the input ends of the transformers;
  • the method further includes: a main controller; the main controller is connected to an inverter controller corresponding to each inverter, and an inverter controller corresponding to each inverter is used as a slave controller;
  • the detecting device sends a fault signal to the inverter controller, specifically: the detecting device sends the fault signal to the main controller, and the main controller sends the fault signal to each inverter Controller
  • the inverter controller is configured to control all inverters to stop according to the fault signal.
  • each inverter corresponds to one inverter controller; the input ends of each inverter are respectively connected to respective corresponding photovoltaic panels;
  • the detecting device detects that a single-phase open-circuit fault occurs on the primary side of the transformer, and sends a fault signal to all inverter controllers;
  • Each of the controller controllers is configured to control a corresponding inverter shutdown according to the fault signal.
  • the secondary side of the transformer is a delta connection; or the secondary side of the transformer is a star connection, and the neutral point is grounded; or, the secondary side of the transformer is a star connection , and the neutral point is not grounded.
  • the detecting device sends a fault signal to the inverter controller, specifically by wire or wireless.
  • Embodiments of the present invention provide a protection method for a photovoltaic grid-connected inverter, which is applied to a photovoltaic grid-connected system, where the photovoltaic grid-connected system includes: a photovoltaic panel, an inverter, a transformer, and a controller; The output end is connected to the input end of the inverter, and the inverter inverts the direct current outputted by the photovoltaic panel into alternating current to the transformer, and the secondary side of the transformer is connected to the output end of the inverter.
  • the primary side of the transformer is connected to the power grid; the primary side of the transformer is a star connection, and the neutral point of the primary side is connected to the earth;
  • the inverter When it is detected that a single-phase open fault occurs on the primary side of the transformer, the inverter is controlled to be shut down.
  • the detecting whether the single-phase open-circuit fault occurs on the primary side of the transformer is specifically: determining whether a single-phase open fault occurs on the primary side by detecting a three-phase current imbalance on the primary side of the transformer;
  • the secondary side of the transformer is a delta connection; or the secondary side of the transformer is a star connection, and the neutral point is grounded;
  • the secondary side of the transformer is a star connection, and the neutral point is not grounded.
  • all inverters are controlled to be stopped.
  • the present invention has the following advantages:
  • a detecting device is disposed between the primary side of the transformer and the power grid, and the detecting device can detect whether a single-phase open circuit fault occurs on the primary side of the transformer, and when the single-phase open circuit fault occurs, the detecting device will detect the fault signal. Sent to the controller on the inverter side, the controller receives the fault signal After the control inverter is stopped. This can avoid the failure of the primary side of the transformer, and the inverter located on the secondary side of the transformer is still running, which causes problems such as overcurrent in the circuit and damage to the transformer.
  • FIG. 1 is a schematic diagram of a photovoltaic grid-connected system with a transformer in the prior art
  • FIG. 2 is a schematic diagram of a first embodiment of a protection system for a photovoltaic grid-connected inverter provided by the present invention
  • FIG. 3a is a schematic diagram of a primary side and a secondary side of a transformer T provided by the present invention
  • FIG. 3b is a transformer T provided by the present invention
  • FIG. 3c is a schematic diagram showing the connection mode of the primary side and the secondary side of the transformer T provided by the present invention
  • FIG. 4 is a second embodiment of the protection system of the photovoltaic grid-connected inverter provided by the present invention.
  • FIG. 5 is a schematic diagram of a third embodiment of a protection system for a photovoltaic grid-connected inverter provided by the present invention
  • FIG. 6 is a flow chart of a first embodiment of a method for protecting a photovoltaic grid-connected inverter provided by the present invention
  • a flow chart of the second embodiment of the method for protecting a photovoltaic grid-connected inverter is provided.
  • FIG. 2 there is shown a schematic diagram of a first embodiment of a protection system for a photovoltaic grid-connected inverter provided by the present invention.
  • the protection system of the photovoltaic grid-connected inverter includes: a detecting device 200, a photovoltaic panel PV, an inverter 100, a transformer T and an inverter controller 300;
  • the output end of the photovoltaic panel PV is connected to the input end of the inverter 100, and the inverter 100 inverts the direct current outputted by the photovoltaic panel PV into alternating current to the transformer T, and the secondary side of the transformer Connecting the output end of the inverter 100, the primary side of the transformer ⁇ is connected to the power grid;
  • the primary side of the transformer ⁇ is a star connection, and the neutral point of the primary side is connected to the earth;
  • the primary side of the transformer ⁇ is star-connected and the neutral point of the primary side is connected to the earth, when the primary side of the transformer ⁇ has a single-phase open-circuit fault, the secondary side of the transformer ⁇ is not affected. The voltage, frequency and phase of the secondary side of the transformer ⁇ remain almost unchanged. Therefore, the inverter 100 located on the secondary side of the transformer ⁇ cannot sense that a single-phase open fault has occurred on the primary side of the transformer ,. In this case, if the inverter 100 continues to operate, an overcurrent will be caused. The problem is therefore that the solution provided by the embodiment detects whether a fault occurs on the primary side of the transformer ,, and feeds the fault information to the secondary side of the transformer ,, thereby controlling the inverter 100 to stop.
  • the detecting device 200 is connected between the primary side of the transformer ⁇ and the power grid;
  • the detecting device 200 is configured to detect whether a single-phase open circuit fault occurs on the primary side of the transformer ;; when a single-phase open circuit fault occurs on the primary side of the transformer ⁇ , a fault signal is sent to the inverter Controller 300;
  • the inverter controller 300 is generally integrated with the inverter 100.
  • the ⁇ 2, ⁇ 2, and C2 are provided with a disconnecting device, which may be a fuse or an air switch or the like.
  • the disconnecting device is a fuse, and when a phase of the primary side of the transformer turns over, the fuse is blown, and the detecting device 200 can detect that a single phase occurs on the primary side of the transformer turns. Open circuit failure.
  • the inverter controller 300 is a controller of the inverter, it is generally integrated with the inverter 100. Therefore, when the primary side of the transformer ⁇ fails, the controller 300 does not perceive it, and the detecting device 200 is required. The result of the detection is sent to the inverter controller 300.
  • the inverter controller 300 is configured to control the inverter 100 to stop according to the fault signal. When a single-phase open circuit fault occurs on the primary side of the transformer , the controller 300 controls the inverter 100 in time. Stop, so that the transformer T can be protected.
  • the detecting device 200 is disposed between the original side of the transformer and the power grid, and the detecting device 200 can detect whether a single-phase open circuit fault occurs on the primary side of the transformer, and when a single-phase open circuit fault occurs, the detection is performed.
  • the device 200 transmits a fault signal to the inverter controller 300 located on the inverter 100 side, and the inverter controller 300 controls the inverter 100 to stop after receiving the fault signal.
  • the primary side of the transformer ⁇ has been prevented from malfunctioning, and the inverter 100 located on the secondary side of the transformer ⁇ is still operating, thereby causing problems such as overcurrent in the circuit, causing the inverter 100 and the transformer ⁇ damage.
  • connection manner of the secondary side of the transformer is not specifically limited in the embodiment of the present invention, and may be various, and will be specifically described below.
  • FIG. 3a there is shown a schematic view of the connection of the primary side and the secondary side of the transformer T provided by the present invention.
  • the secondary side of the transformer in Figure 3a is a delta connection.
  • Fig. 3a the three-phase windings of the secondary side of the transformer are represented by lowercase x, y, z. It can be seen that x, y, z are connected end to end in sequence, and are connected in a triangle, which is called a delta connection.
  • FIG. 3b the figure is a schematic view showing the connection mode of the primary side and the secondary side of the transformer T provided by the present invention.
  • the secondary side of the transformer in Fig. 3b is connected in the same manner as the primary side of the transformer, and is connected in a star shape, and the neutral point is grounded.
  • FIG. 3c the figure is a three-way diagram of the connection between the primary side and the secondary side of the transformer T provided by the present invention.
  • the secondary side of the transformer in Figure 3c is a star connection and the neutral point is not grounded.
  • FIG. 4 the figure is a schematic diagram of a second embodiment of a protection system for a photovoltaic grid-connected inverter provided by the present invention.
  • an inverter is taken as an example. It can be understood that, in actual operation, a plurality of inverters are generally operated in parallel. In this embodiment, the working principle of multiple inverters in parallel operation is described.
  • Figure 4 shows an example in which n inverters are operated in parallel.
  • n is an integer greater than or equal to 2. It can be understood that when the inverter is greater than or equal to 2, it can be understood that multiple inverters are operated in parallel. As long as a plurality of inverters are operated in parallel, the operation principle is the same, and the number of inverters is not specifically limited in the present invention.
  • each inverter corresponds to one controller; as shown in FIG. 4, the first inverter 100-1 corresponds to the first inverter controller 300. -1, the second inverter 100-2 corresponds to the second inverter controller 300-2, and the nth inverter 100-n corresponds to the nth inverter controller 300-n.
  • each inverter is respectively connected to the corresponding photovoltaic panels; as shown in FIG. 4, the input end of the first inverter 100-1 is connected to PV1, and the input end of the second inverter 100-2 is connected. PV2, the input of the nth inverter 100-n is connected to PVn.
  • the output of all inverters is connected to the secondary side of the transformer T; as shown in Figure 4, the primary side of the transformer T is 8, B, C; the secondary side of the transformer T is &, b, c.
  • the detecting device 200 When the detecting device 200 detects that a single-phase open fault occurs on the primary side of the transformer T, it sends a fault signal to all controllers; that is, the detecting device 200 connects all the controllers, as shown in FIG. 4, the detecting device 200
  • the first inverter controller 300-1 is connected while the second inverter controller 300-2 and the nth inverter controller 300-n are connected.
  • Each of the controllers is configured to control a corresponding inverter shutdown according to the fault signal.
  • the first inverter controller 300-1 controls the first inverter 100-1
  • the second inverter controller 300-2 controls the second inverter 100-2
  • nth The controller controls the nth inverter 100-n.
  • the detecting device 200 may be a three-phase current imbalance detection, a leakage detection, or other method capable of detecting a phase failure, and may also assist in phase loss detection, phase sequence detection, overcurrent detection, and the like.
  • the function is to detect single-phase disconnection of the power grid at this time, and the current appears to be uneven.
  • the flow condition or the current flowing through the N line has a large abnormal value.
  • phase A is disconnected, phase A current is 0, and phase B and phase C currents are re-originated.
  • phase A current is 0, and phase B and phase C currents are re-originated.
  • phase B and phase C currents are re-originated.
  • there will be a large current imbalance such as the AB two phase imbalance, the AC two phases appear imbalance.
  • a single-phase open-circuit fault is detected on the primary side by detecting the current flowing through the N-line on the primary side of the transformer. Since any one phase is open, the N line current will also vary greatly.
  • the detecting device may be connected in series between the transformer T and the power grid, or may be connected in parallel between the transformer T and the power grid.
  • the detecting device sends a fault signal to the inverter controller, which can be sent by wire or wirelessly.
  • the protection system of the photovoltaic grid-connected inverter detects that a fault occurs on the primary side of the transformer T through the detecting device 200, and sends a fault signal to all controllers on the secondary side of the transformer T, all controllers. Control the corresponding inverter shutdown separately, so that all inverters can be protected.
  • System Embodiment 3
  • FIG. 5 the figure is a schematic diagram of a third embodiment of a protection system for a photovoltaic grid-connected inverter provided by the present invention.
  • the detecting device directly sends a fault signal to the inverter controller corresponding to each inverter, and the difference between this embodiment and the system embodiment 2 is that all the inverters in this embodiment share one.
  • the main controller detects the device to send a fault signal to the main controller, and the main controller sends a fault signal to each inverter controller. At this time, each inverter controller belongs to the slave controller. As shown in Figure 5.
  • each inverter controller is integrated with its corresponding inverter.
  • the first inverter 100-1 and the second inverter 100-2 are connected to the main controller 400 until the inverter controller corresponding to the nth inverter 100-n.
  • the detecting device 200 When the detecting device 200 detects that a fault occurs on the primary side of the transformer T, it transmits a fault signal to the main controller 400.
  • the main controller 400 transmits a fault signal to each slave controller, that is, the first inverter controller 300-1.
  • the second inverter controller 300-2 is up to the nth inverter controller 300-n, and then each inverter controller controls the corresponding inverter to stop.
  • the embodiment of the invention further provides a protection method for the photovoltaic grid-connected inverter, and the working flow thereof is described below with reference to the accompanying drawings.
  • FIG. 6 the figure is a flow chart of a method for protecting a photovoltaic grid-connected inverter provided by the present invention.
  • the protection method of the photovoltaic grid-connected inverter provided in this embodiment is applied to a photovoltaic grid-connected system, wherein the photovoltaic grid-connected system comprises: a photovoltaic panel, an inverter, a transformer and a controller; and an output end of the photovoltaic panel Connecting an input end of the inverter, the inverter inverting direct current outputted by the photovoltaic panel to alternating current to the transformer, and a secondary side of the transformer is connected to an output end of the inverter, the transformer
  • the primary side is connected to the power grid; the primary side of the transformer is a star connection, and the neutral point of the primary side is connected to the earth; the following steps are included:
  • S601 detecting whether a single-phase open circuit fault occurs on a primary side of the transformer
  • the primary side of the transformer is a star connection and the neutral point of the primary side is connected to the earth, when the primary side of the transformer has a single-phase open circuit fault, the secondary side of the transformer is not affected. The voltage, frequency and phase of the secondary side remain almost unchanged. Therefore, the inverter located on the secondary side of the transformer cannot sense that a single-phase open fault has occurred on the primary side of the transformer. In this case, if the inverter continues to operate, problems such as overcurrent will occur.
  • the solution provided in this embodiment detects whether a fault occurs on the primary side of the transformer, and feeds the fault information to the secondary side of the transformer, thereby controlling the inverter to stop.
  • the inverter When a single-phase open-circuit fault occurs on the primary side of the transformer, the inverter is stopped in time to protect the transformer.
  • whether the single-phase open fault occurs on the primary side of the transformer can be detected on the primary side of the transformer, and when the single-phase open fault occurs, the inverter is controlled to stop. This will prevent the primary side of the transformer from failing, and the inverter on the secondary side of the transformer will continue to operate. This causes problems such as overcurrent in the circuit and causes damage to the transformer.
  • the secondary side of the transformer may be a delta connection.
  • the secondary side of the transformer is a star connection, and the neutral point is grounded;
  • the secondary side of the transformer is a star connection, and the neutral point is not grounded.
  • connection method of the secondary side of the transformer can be seen in Figure 3a - Figure 3c.
  • Method Embodiment 2
  • FIG. 7 the figure is a flow chart of Embodiment 2 of a method for protecting a photovoltaic grid-connected inverter provided by the present invention.
  • S701 determining whether a single-phase open circuit fault occurs on the primary side by detecting a three-phase current imbalance on the primary side of the transformer; or determining whether a primary phase open fault occurs on the primary side by detecting a leakage current on a primary side of the transformer. If yes, execute S702;
  • the detecting device may be a three-phase current imbalance detection, a leakage detection or other method capable of detecting a phase failure, and may also assist in the functions of phase loss detection, phase sequence detection, overcurrent detection, etc.
  • a large uneven current occurs in the current or a large abnormal value occurs in the current flowing through the N line.
  • the protection method of the photovoltaic grid-connected inverter when detecting the failure of the primary side of the transformer, all the inverters on the secondary side of the control transformer are stopped, and the problem of overcurrent is prevented, so that the protection can be timely All inverters.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

提供了一种光伏并网逆变器的保护系统，包括：检测装置（200）、光伏板（PV）、逆变器（100）、变压器（T）和逆变器控制器（300）；所述光伏板（PV）的输出端连接所述逆变器（100）的输入端，所述逆变器（100）将光伏板（PV）输出的直流电逆变为交流电传输给所述变压器（T）；所述变压器（T）的副边连接所述逆变器（100）的输出端，所述变压器（T）的原边连接电网；所述检测装置（200）连接在所述变压器（T）的原边与电网之间，用于检测所述变压器（T）的原边侧是否发生单相开路故障；当检测到所述变压器（T）的原边侧发生单相开路故障时，发送故障信号给所述逆变器控制器（300）；所述逆变器控制器（300），用于根据所述故障信号控制所述逆变器（100）停机。还提供了一种光伏并网逆变器的保护方法。

Description

一种光伏并网逆变器的保护系统及方法 技术领域 本发明涉及一种光伏发电技术领域，尤其涉及一种光伏并网逆变器的保护 系统及方法。
背景技术
随着世界上能源的日益紧缺， 现在越来越多的区域开始利用光伏发电。 由 于光伏板输出的电能为直流电， 因此， 需要逆变器将直流电逆变为交流电馈送 到电网上， 这个过程称为逆变并网。
一般为了隔离， 逆变器与电网之间还连接有变压器， 下面结合附图介绍带 变压器的光伏并网系统。
参见图 1， 该图为现有技术中的带有变压器的光伏并网系统示意图。
图 1中所示的 PV为光伏板， PV输出的为直流电， 经过逆变器 100逆变 为交流电， 交流电经过变压器 T隔离后将能量输送给电网。
为了描述方便， 定义变压器 T连接电网的一侧为原边（A、 B、 C )， 变压 器 T连接逆变器 100的一侧为副边（a、 b、 c ) 。
需要说明的是， 变压器 T的原边（A、 B、 C )三相连接为星形， 并且中性 点 N接大地。 这种连接方式的变压器， 当变压器 T的原边侧， 即电网侧发生 三相中的任意一相开路故障时， 变压器 T的副边侧的电压、频率和相位几乎与 正常状态时没有区别。 即， 当变压器 T的原边发生故障时， 变压器 T的副边 感应不到故障， 这样逆变器就会继续运行。 但是由于发生了故障， 会造成变压 器上产生过流问题， 最终导致变压器的损坏。
因此， 本领域技术人员需要提供一种光伏并网逆变器的保护系统及方法， 能够在电网侧发生故障时， 及时保护光伏并网逆变器以及变压器。
发明内容
本发明提供一种光伏并网逆变器的保护系统及方法，能够在电网侧发生故 障时， 及时保护光伏并网逆变器以及变压器。
本实施例提供一种光伏并网逆变器的保护系统， 包括：检测装置、光伏板、 逆变器、 变压器和逆变器控制器； 所述光伏板的输出端连接所述逆变器的输入端，所述逆变器将光伏板输出 的直流电逆变为交流电传输给所述变压器，所述变压器的副边连接所述逆变器 的输出端， 所述变压器的原边连接电网；
所述变压器的原边为星型接法， 且原边的中性点接大地；
所述检测装置连接在所述变压器的原边与电网之间；
所述检测装置， 用于检测所述变压器的原边侧是否发生单相开路故障； 当 检测到所述变压器的原边侧发生单相开路故障时，发送故障信号给所述逆变器 控制器；
所述逆变器控制器， 用于根据所述故障信号控制所述逆变器停机。
优选地， 所述检测装置检测到所述变压器的原边侧发生单相开路故障， 具 体为：
通过检测所述变压器原边侧的三相电流不平衡判断原边是否出现单相开 路故障； 或，
通过检测所述变压器原边侧的流过 N 线的电流来判断原边是否出现单相 开路故障。
优选地， 当所述逆变器为多台时， 每台逆变器的输入端分别连接各自对应 的光伏板； 所有逆变器的输出端均连接所述变压器的输入端；
还包括：主控制器；所述主控制器与每台逆变器对应的逆变器控制器连接， 每台逆变器对应的逆变器控制器作为从控制器；
所述检测装置发送故障信号给所述逆变器控制器， 具体为： 所述检测装置 发送所述故障信号给所述主控制器，所述主控制器再发送所述故障信号给各个 逆变器控制器；
所述逆变器控制器， 用于根据所述故障信号控制所有逆变器均停机。
优选地， 当所述逆变器为多台时， 每个逆变器对应一个逆变器控制器； 每台逆变器的输入端分别连接各自对应的光伏板；
所有逆变器的输出端均连接所述变压器的输入端；
所述检测装置检测到所述变压器的原边侧发生单相开路故障时，发送故障 信号给所有逆变器控制器；
每个所述控制器控制器， 用于根据所述故障信号控制对应的逆变器停机。 优选地， 所述变压器的副边侧为三角形接法； 或， 所述变压器的副边侧为 星型接法， 并且中性点接地； 或， 所述变压器的副边侧为星型接法， 并且中性 点不接地。
优选地， 所述检测装置发送故障信号给所述逆变器控制器， 具体通过有线 方式或无线方式发送。
本发明实施例提供一种光伏并网逆变器的保护方法，应用于光伏并网系统 中， 所述光伏并网系统包括： 光伏板、 逆变器、 变压器和控制器； 所述光伏板 的输出端连接所述逆变器的输入端，所述逆变器将光伏板输出的直流电逆变为 交流电传输给所述变压器， 所述变压器的副边连接所述逆变器的输出端， 所述 变压器的原边连接电网； 所述变压器的原边为星型接法，且原边的中性点接大 地；
包括以下步骤：
检测所述变压器的原边侧是否发生单相开路故障；
当检测到所述变压器的原边侧发生单相开路故障时， 控制所述逆变器停 机。
优选地， 所述检测所述变压器的原边侧是否发生单相开路故障， 具体为： 通过检测所述变压器原边侧的三相电流不平衡判断原边是否出现单相开 路故障；
或，
通过检测所述变压器原边侧的漏电流来判断原边是否出现单相开路故障。 优选地， 所述变压器的副边侧为三角形接法； 或， 所述变压器的副边侧为 星型接法， 并且中性点接地；
或，
所述变压器的副边侧为星型接法， 并且中性点不接地。
优选地， 当所述逆变器为多台时， 控制所有逆变器均停机。
与现有技术相比， 本发明具有以下优点：
本实施例提供的系统， 在变压器原边侧和电网之间设置检测装置， 检测装 置可以检测出变压器的原边侧是否发生单相开路故障， 当发生单相开路故障 时，检测装置将故障信号发送给位于逆变器侧的控制器，控制器收到故障信号 后控制逆变器停机。这样可以避免变压器的原边侧已经发生故障了， 而位于变 压器的副边侧的逆变器还在运行， 进而造成电路中出现过电流等问题，对变压 器造成损坏。
附图说明 为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施 例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地， 下面描述 中的附图仅仅是本发明的一些实施例， 对于本领域普通技术人员来讲，在不付 出创造性劳动的前提下， 还可以根据这些附图获得其他的附图。
图 1是现有技术中的带有变压器的光伏并网系统示意图；
图 2是本发明提供的光伏并网逆变器的保护系统实施例一示意图； 图 3a是本发明提供的变压器 T的原边和副边连接方式一示意图； 图 3b是本发明提供的变压器 T的原边和副边连接方式二示意图； 图 3c是本发明提供的变压器 T的原边和副边连接方式三示意图； 图 4是本发明提供的光伏并网逆变器的保护系统实施例二示意图； 图 5是本发明提供的光伏并网逆变器的保护系统实施例三示意图； 图 6是本发明提供的光伏并网逆变器的保护方法实施例一流程图； 图 7是本发明提供的光伏并网逆变器的保护方法实施例二流程图。
具体实施方式 下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清 楚、 完整地描述， 显然， 所描述的实施例仅仅是本发明一部分实施例， 而不是 全部的实施例。基于本发明中的实施例， 本领域普通技术人员在没有做出创造 性劳动前提下所获得的所有其他实施例， 都属于本发明保护的范围。
为使本发明的上述目的、 特征和优点能够更加明显易懂， 下面结合附图对 本发明的具体实施方式做详细的说明。
系统实施例一：
参见图 2， 该图为本发明提供的光伏并网逆变器的保护系统实施例一示意 图。
本实施例提供的光伏并网逆变器的保护系统， 包括： 检测装置 200、 光伏 板 PV、 逆变器 100、 变压器 T和逆变器控制器 300; 所述光伏板 PV的输出端连接所述逆变器 100的输入端， 所述逆变器 100 将光伏板 PV输出的直流电逆变为交流电传输给所述变压器 T， 所述变压器 Τ 的副边连接所述逆变器 100的输出端， 所述变压器 Τ的原边连接电网；
所述变压器 Τ的原边为星型接法， 且原边的中性点接大地；
需要说明的是， 由于变压器 Τ的原边为星型接法， 并且原边的中性点接大 地， 因此， 当变压器 Τ的原边发生单相开路故障时， 变压器 Τ的副边不受影 响， 变压器 Τ的副边的电压、 频率和相位几乎保持不变。 因此， 位于变压器 Τ 的副边侧的逆变器 100无法感知变压器 Τ的原边侧已经发生了单相开路故障， 在这种情况下， 如果逆变器 100继续运行， 将会造成过电流等问题， 因此， 本 实施例提供的方案在变压器 Τ的原边侧检测是否发生故障，而将故障信息反馈 到变压器 Τ的副边侧， 进而控制逆变器 100停机。
所述检测装置 200连接在所述变压器 Τ的原边与电网之间；
所述检测装置 200， 用于检测所述变压器 Τ的原边侧是否发生单相开路故 障； 当检测到所述变压器 Τ的原边侧发生单相开路故障时，发送故障信号给所 述逆变器控制器 300;
可以理解的是， 逆变器控制器 300—般是和逆变器 100集成在一起的。 需要说明的是， 所述 Α2、 Β2和 C2处设置有断开装置， 该断开装置可以 为保险丝或空气开关等。 例如， 断开装置为保险丝， 当变压器 Τ的原边侧的某 一相发生过流时， 该保险丝被烧断， 此时所述检测装置 200便可以检测出现变 压器 Τ的原边侧发生单相开路故障。
需要说明的是， 其他类别的故障， 例如， 相序错误， 过电压、 欠电压以及 过电流等故障， 可以在逆变器侧， 即变压器的副边侧检测到， 因此， 本实施例 中不着重介绍这些情况， 可以理解的是， 发生这些故障时， 也需要控制逆变器 停机。
由于逆变器控制器 300是逆变器的控制器， 因此一般与逆变器 100集成在 一起， 因此， 变压器 Τ的原边侧发生故障时， 控制器 300并不能感知到， 需要 检测装置 200将检测的结果发送给逆变器控制器 300。
所述逆变器控制器 300，用于根据所述故障信号控制所述逆变器 100停机。 当变压器 Τ的原边发生单相开路故障时， 控制器 300及时控制逆变器 100 停机， 从而可以保护变压器 T。
本实施例提供的系统， 在变压器 Τ原边侧和电网之间设置检测装置 200， 检测装置 200可以检测出变压器 Τ的原边侧是否发生单相开路故障，当发生单 相开路故障时，检测装置 200将故障信号发送给位于逆变器 100侧的逆变器控 制器 300， 逆变器控制器 300收到故障信号后控制逆变器 100停机。 这样可以 避免变压器 Τ的原边侧已经发生故障了， 而位于变压器 Τ的副边侧的逆变器 100还在运行， 进而造成电路中出现过电流等问题， 对逆变器 100和变压器 Τ 造成损坏。
对于变压器 Τ的副边的连接方式， 本发明实施例中不做具体限定， 可以为 多种， 下面具体说明。
需要说明的是图 3a-图 3c中变压器的原边的连接方式均相同。均是星型接 法， 并且中性点接大地。
参见图 3a， 该图为本发明提供的变压器 T的原边和副边连接方式一示意 图。
图 3a中的变压器的副边侧为三角形接法。
从图 3a中可以看出， 变压器的副边的三相绕组用小写的 x、 y、 z表示， 可以看出， x、 y、 z依次首尾相连， 连接成三角形， 称为三角形连接。
参见图 3b， 该图为本发明提供的变压器 T的原边和副边连接方式二示意 图。
图 3b中的所述变压器的副边侧的连接方式与变压器的原边侧的连接方式 相同， 均为星型接法， 并且中性点接地。
参见图 3c， 该图为本发明提供的变压器 T的原边和副边连接方式三示意 图。
图 3c中的变压器的副边侧为星型接法， 并且中性点不接地。
需要说明的是， 以上仅列举了几种变压器的原边和副边的绕组连接方式， 当然不局限于以上列举的几种。 另外， 本发明实施例中不限定同名端， 例如同 名端可以为 Aa、 Bb、 Cc时， 变压器的同名端可以表示为 YD11， 其中 Y代表 原边是星型接法， D代表副边是三角形接法。 系统实施例二：
参见图 4， 该图为本发明提供的光伏并网逆变器的保护系统实施例二示意 图。
系统实施例一中是以一台逆变器为例进行介绍的， 可以理解的是， 实际运 行时， 一般多台逆变器并联运行。本实施例中介绍多台逆变器并联运行时的工 作原理。
图 4以 n台逆变器并联运行为例进行介绍， n为大于或等于 2的整数。 可 以理解的是，逆变器大于或等于 2台时均可以理解为多台逆变器并联运行。 只 要是多台逆变器并联运行， 其工作原理是相同的， 本发明中不具体限定逆变器 的台数。
本实施例中， 当所述逆变器为多台时， 每个逆变器对应一个控制器； 如图 4所示，第一台逆变器 100-1对应第一逆变器控制器 300-1，第二台逆变器 100-2 对应第二逆变器控制器 300-2， 第 n 台逆变器 100-n对应第 n逆变器控制器 300-n。
每台逆变器的输入端分别连接各自对应的光伏板； 如图 4所示， 第一台逆 变器 100-1的输入端连接 PV1， 第二台逆变器 100-2的输入端连接 PV2， 第 n 台逆变器 100-n的输入端连接 PVn。
所有逆变器的输出端均连接所述变压器 T的副边； 如图 4所示， 变压器 T 的原边为八、 B、 C; 变压器 T的副边为 &、 b、 c。
所述检测装置 200检测到所述变压器 T的原边侧发生单相开路故障时，发 送故障信号给所有控制器； 即，检测装置 200连接所有的控制器，如图 4所示， 检测装置 200连接第一逆变器控制器 300-1，同时连接第二逆变器控制器 300-2 以及第 n逆变器控制器 300-n。
每个所述控制器， 用于根据所述故障信号控制对应的逆变器停机。 如图 4 所示， 第一逆变器控制器 300-1控制第一台逆变器 100-1， 第二逆变器控制器 300-2控制第二台逆变器 100-2， 第 n控制器控制第 n台逆变器 100-n。
需要说明的是， 检测装置 200可以为三相电流不平衡检测、 漏电检测或者 其他能检测到出现断相的方法， 当然也可以辅助缺相检测、 相序检测、 过流检 测等功能， 其主要功能为检测到此时的电网出现单相断开， 电流出现较大不均 流的情况或者流过 N线的电流出现较大的异常值。
例如，通过检测所述变压器原边侧的三相电流不平衡判断原边是否出现单 相开路故障； 例如 A相断开， 则 A相电流为 0， 而 B相和 C相电流则会再原 来的基础上再增加，故会出现较大的电流不平衡，如 AB两相出现不平衡， AC 两相出现不平衡。
或，
通过检测所述变压器原边侧的流过 N 线的电流来判断原边是否出现单相 开路故障。 由于任何一相开路， 则 N线电流也会有较大的变化。
需要说明的是， 所述检测装置可以串联在变压器 T和电网之间， 也可以并 联在变压器 T和电网之间。
需要说明的是，检测装置发送故障信号给逆变器控制器可以通过有线的方 式发送， 也可以通过无线的方式发送。
本实施例提供的光伏并网逆变器的保护系统， 通过检测装置 200， 检测出 变压器 T的原边侧发生故障时， 给变压器 T的副边侧的所有控制器发送故障 信号， 所有控制器分别控制对应的逆变器停机， 这样可以保护所有的逆变器。 系统实施例三：
参见图 5， 该图为本发明提供的光伏并网逆变器的保护系统实施例三示意 图。
系统实施例二中是检测装置直接发送故障信号给每台逆变器对应的逆变 器控制器， 而本实施例与系统实施例二的区别是， 本实施例中所有的逆变器共 用一个主控制器，检测装置先发故障信号给主控制器， 主控制器再将故障信号 发送给各个逆变器控制器，此时各个逆变器控制器属于从控制器。如图 5所示。
可以理解的是，一般各个逆变器控制器是与各自对应的逆变器集成在一起 的。
第一台逆变器 100-1、 第二台逆变器 100-2直到第 n台逆变器 100-n对应 的逆变器控制器均连接主控制器 400。
检测装置 200检测到变压器 T的原边出现故障，则发送故障信号给主控制 器 400。 主控制器 400将故障信号发送给各个从控制器， 即第一逆变器控制器 300-1、 第二逆变器控制器 300-2直到第 n逆变器控制器 300-n， 然后各个逆变 器控制器控制对应的逆变器停机。 基于以上实施例提供的光伏并网逆变器的保护系统，本发明实施例还提供 一种光伏并网逆变器的保护方法， 下面结合附图来介绍其工作流程。
方法实施例一：
参见图 6， 该图为本发明提供的光伏并网逆变器的保护方法实施例一流程 图。
本实施例提供的光伏并网逆变器的保护方法， 应用于光伏并网系统中， 所 述光伏并网系统包括： 光伏板、 逆变器、 变压器和控制器； 所述光伏板的输出 端连接所述逆变器的输入端，所述逆变器将光伏板输出的直流电逆变为交流电 传输给所述变压器， 所述变压器的副边连接所述逆变器的输出端， 所述变压器 的原边连接电网； 所述变压器的原边为星型接法， 且原边的中性点接大地； 包括以下步骤：
S601 : 检测所述变压器的原边侧是否发生单相开路故障；
S602: 当检测到所述变压器的原边侧发生单相开路故障时， 控制所述逆变 器停机。
需要说明的是，由于变压器的原边为星型接法，并且原边的中性点接大地， 因此， 当变压器的原边发生单相开路故障时， 变压器的副边不受影响， 变压器 的副边的电压、 频率和相位几乎保持不变。 因此， 位于变压器的副边侧的逆变 器无法感知变压器的原边侧已经发生了单相开路故障，在这种情况下，如果逆 变器继续运行， 将会造成过电流等问题， 因此， 本实施例提供的方案在变压器 的原边侧检测是否发生故障， 而将故障信息反馈到变压器的副边侧， 进而控制 逆变器停机。
当变压器的原边发生单相开路故障时， 及时控制逆变器停机， 从而可以保 护变压器。
本实施例提供的系统，在变压器原边侧可以检测出变压器的原边侧是否发 生单相开路故障， 当发生单相开路故障时， 控制逆变器停机。 这样可以避免变 压器的原边侧已经发生故障了， 而位于变压器的副边侧的逆变器还在继续运 行， 进而造成电路中出现过电流等问题， 对变压器造成损坏。
需要说明的是， 所述变压器的副边侧可以为三角形接法。
另外， 所述变压器的副边侧为星型接法， 并且中性点接地；
或，
所述变压器的副边侧为星型接法， 并且中性点不接地。
变压器副边的连接方式具体可以参见图 3a-图 3c。 方法实施例二：
参见图 7， 该图为本发明提供的光伏并网逆变器的保护方法实施例二流程 图。
S701：通过检测所述变压器原边侧的三相电流不平衡判断原边是否出现单 相开路故障； 或，通过检测所述变压器原边侧的漏电流来判断原边是否出现单 相开路故障。 如果是， 则执行 S702;
需要说明的是， 检测装置可以为三相电流不平衡检测、 漏电检测或者其他 能检测到出现断相的方法， 当然也可以辅助缺相检测、 相序检测、 过流检测等 功能， 其主要功能为检测到此时的电网出现单相断开， 电流出现较大不均流的 情况或者流过 N线的电流出现较大的异常值。
S702: 所述逆变器为多台时， 控制所有逆变器均停机。
本实施例提供的光伏并网逆变器的保护方法，检测出变压器的原边侧发生 故障时， 控制变压器副边侧的所有逆变器均停机， 防止发生过流等问题， 这样 可以及时保护所有的逆变器。
以上所述， 仅是本发明的较佳实施例而已， 并非对本发明作任何形式上的 限制。 虽然本发明已以较佳实施例揭露如上， 然而并非用以限定本发明。 任何 熟悉本领域的技术人员，在不脱离本发明技术方案范围情况下，都可利用上述 揭示的方法和技术内容对本发明技术方案做出许多可能的变动和修饰，或修改 为等同变化的等效实施例。 因此， 凡是未脱离本发明技术方案的内容， 依据本 发明的技术实质对以上实施例所做的任何简单修改、等同变化及修饰， 均仍属 于本发明技术方案保护的范围内。

Claims

权 利 要 求
1、 一种光伏并网逆变器的保护系统， 其特征在于， 包括： 检测装置、 光 伏板、 逆变器、 变压器和逆变器控制器；
所述光伏板的输出端连接所述逆变器的输入端，所述逆变器将光伏板输出 的直流电逆变为交流电传输给所述变压器，所述变压器的副边连接所述逆变器 的输出端， 所述变压器的原边连接电网；
所述变压器的原边为星型接法， 且原边的中性点接大地；
所述检测装置连接在所述变压器的原边与电网之间；
所述检测装置， 用于检测所述变压器的原边侧是否发生单相开路故障； 当 检测到所述变压器的原边侧发生单相开路故障时，发送故障信号给所述逆变器 控制器；
所述逆变器控制器， 用于根据所述故障信号控制所述逆变器停机。
2、 根据权利要求 1所述的光伏并网逆变器的保护系统， 其特征在于， 所 述检测装置检测到所述变压器的原边侧发生单相开路故障， 具体为：
通过检测所述变压器原边侧的三相电流不平衡判断原边是否出现单相开 路故障； 或，
通过检测所述变压器原边侧的流过 N 线的电流来判断原边是否出现单相 开路故障。
3、 根据权利要求 1或 2所述的光伏并网逆变器的保护系统， 其特征在于， 当所述逆变器为多台时，每台逆变器的输入端分别连接各自对应的光伏板； 所 有逆变器的输出端均连接所述变压器的输入端；
还包括：主控制器；所述主控制器与每台逆变器对应的逆变器控制器连接， 每台逆变器对应的逆变器控制器作为从控制器；
所述检测装置发送故障信号给所述逆变器控制器， 具体为： 所述检测装置 发送所述故障信号给所述主控制器，所述主控制器再发送所述故障信号给各个 逆变器控制器；
所述逆变器控制器， 用于根据所述故障信号控制所有逆变器均停机。
4、 根据权利要求 1或 2所述的光伏并网逆变器的保护系统， 其特征在于， 当所述逆变器为多台时， 每个逆变器对应一个逆变器控制器； 每台逆变器的输入端分别连接各自对应的光伏板；
所有逆变器的输出端均连接所述变压器的输入端；
所述检测装置检测到所述变压器的原边侧发生单相开路故障时，发送故障 信号给所有逆变器控制器；
每个所述控制器控制器， 用于根据所述故障信号控制对应的逆变器停机。
5、 根据权利要求 1所述的光伏并网逆变器的保护系统， 其特征在于， 所 述变压器的副边侧为三角形接法； 或， 所述变压器的副边侧为星型接法， 并且 中性点接地； 或， 所述变压器的副边侧为星型接法， 并且中性点不接地。
6、 根据权利要求 1所述的光伏并网逆变器的保护系统， 其特征在于， 所 述检测装置发送故障信号给所述逆变器控制器，具体通过有线方式或无线方式 发送。
7、 一种光伏并网逆变器的保护方法， 其特征在于， 应用于光伏并网系统 中， 所述光伏并网系统包括： 光伏板、 逆变器、 变压器和控制器； 所述光伏板 的输出端连接所述逆变器的输入端，所述逆变器将光伏板输出的直流电逆变为 交流电传输给所述变压器， 所述变压器的副边连接所述逆变器的输出端， 所述 变压器的原边连接电网； 所述变压器的原边为星型接法，且原边的中性点接大 地；
包括以下步骤：
检测所述变压器的原边侧是否发生单相开路故障；
当检测到所述变压器的原边侧发生单相开路故障时， 控制所述逆变器停 机。
8、 根据权利要求 7所述的光伏并网逆变器的保护方法， 其特征在于， 所 述检测所述变压器的原边侧是否发生单相开路故障， 具体为：
通过检测所述变压器原边侧的三相电流不平衡判断原边是否出现单相开 路故障；
或，
通过检测所述变压器原边侧的漏电流来判断原边是否出现单相开路故障。
9、 根据权利要求 7或 8所述的光伏并网逆变器的保护方法， 其特征在于， 所述变压器的副边侧为三角形接法； 或， 所述变压器的副边侧为星型接法， 并 且中性点接地；
或，
所述变压器的副边侧为星型接法， 并且中性点不接地。
10、 根据权利要求 7所述的光伏并网逆变器的保护方法， 其特征在于， 当 所述逆变器为多台时， 控制所有逆变器均停机。
PCT/CN2014/083622 2014-08-04 2014-08-04 一种光伏并网逆变器的保护系统及方法 Ceased WO2016019491A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
CA2953834A CA2953834C (en) 2014-08-04 2014-08-04 Protection system and method for photovoltaic grid-connected inverter
US15/324,101 US20170207693A1 (en) 2014-08-04 2014-08-04 Protection system and method for photovoltaic grid-connected inverter
CN201480079927.7A CN106463968B (zh) 2014-08-04 2014-08-04 一种光伏并网逆变器的保护系统及方法
PCT/CN2014/083622 WO2016019491A1 (zh) 2014-08-04 2014-08-04 一种光伏并网逆变器的保护系统及方法

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2014/083622 WO2016019491A1 (zh) 2014-08-04 2014-08-04 一种光伏并网逆变器的保护系统及方法

Publications (1)

Publication Number Publication Date
WO2016019491A1 true WO2016019491A1 (zh) 2016-02-11

Family

ID=55262975

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2014/083622 Ceased WO2016019491A1 (zh) 2014-08-04 2014-08-04 一种光伏并网逆变器的保护系统及方法

Country Status (4)

Country Link
US (1) US20170207693A1 (zh)
CN (1) CN106463968B (zh)
CA (1) CA2953834C (zh)
WO (1) WO2016019491A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108183461A (zh) * 2018-03-05 2018-06-19 温州科宇电器有限公司 一种光伏电站电流方向保护方法及中央控制模块
US20230121559A1 (en) * 2021-10-15 2023-04-20 Caterpillar Inc. Open phase detection

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11329573B2 (en) * 2017-08-04 2022-05-10 Panasonic Intellectual Property Management Co., Ltd. Power converter and power conversion system
WO2020020469A1 (de) * 2018-07-27 2020-01-30 Siemens Aktiengesellschaft Energieerzeuger-anlage
CN110571841A (zh) * 2019-07-10 2019-12-13 台州宏达电力建设有限公司台州经济开发区运检分公司 变频输电系统
EP3846337B1 (en) * 2019-12-30 2025-09-10 Solaredge Technologies Ltd. Energy harvesting and electrical power generation
CN111262767B (zh) * 2020-03-27 2022-11-15 阳光电源股份有限公司 一种光伏系统及其通信方法
CN112017072B (zh) * 2020-08-26 2024-05-14 阳光电源（上海）有限公司 光伏系统、组串内设备的定位方法和mlpe设备及其排序方法
CN112072699B (zh) * 2020-09-03 2023-08-01 深圳市禾望科技有限公司 光伏逆变器及其控制方法
CN115184839A (zh) * 2022-07-26 2022-10-14 合肥工业大学 一种级联h桥并网逆变器系统的开路故障功率管定位方法
DE102023111797B4 (de) * 2023-05-05 2025-06-12 Bayerische Motoren Werke Aktiengesellschaft Umrichter und Verfahren zum Betreiben eines Gleichstromversorgungsnetzes
CN116846193B (zh) * 2023-07-13 2024-05-28 山东元绅智能科技有限公司 一种光伏并网逆变器及其使用方法
CN120855499A (zh) * 2025-09-24 2025-10-28 锦浪科技股份有限公司 一种多逆变器并网控制系统及其工作方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1658465A (zh) * 2005-03-15 2005-08-24 清华大学 兼备无功与谐波补偿功能的光伏并网装置
US20090244938A1 (en) * 2008-03-31 2009-10-01 Sma Solar Technology Ag Switching apparatus for grounding an inverter
CN102738827A (zh) * 2012-06-20 2012-10-17 天津电气传动设计研究所 一种用于三相并网光伏逆变器的低电压穿越控制方法
CN202651808U (zh) * 2012-06-20 2013-01-02 天津电气传动设计研究所 一种电网电压直接前馈的三相并网光伏逆变器系统
CN203466576U (zh) * 2013-08-12 2014-03-05 深圳市合兴加能科技有限公司 一种本质安全型光伏接地系统
CN103647453A (zh) * 2013-12-13 2014-03-19 中南大学 一种基于ccm模式的微逆变器及其控制方法
CN103915856A (zh) * 2014-04-17 2014-07-09 中南大学 一种基站并网-充电光伏微逆变器系统及其控制方法

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8228699B2 (en) * 2007-02-22 2012-07-24 Mitsubishi Electric Corporation Power converting apparatus including half-bridge inverters connected between positive and negative terminals of a DC power supply
US8401706B2 (en) * 2008-08-28 2013-03-19 ETM Electromatic Networked multi-inverter maximum power-point tracking
US8614525B2 (en) * 2010-12-21 2013-12-24 General Electric Company Methods and systems for operating a power generation system
CN102222937B (zh) * 2011-06-22 2013-11-27 常熟开关制造有限公司(原常熟开关厂） 一种光伏并网逆变器及其并网控制方法
CN103378603B (zh) * 2012-04-24 2017-03-01 通用电气公司 开路故障检测装置，变流器控制器，能量转换系统和方法
CN202978745U (zh) * 2012-11-20 2013-06-05 宋厚山 光伏发电的功率调节器
CN103532214A (zh) * 2013-09-17 2014-01-22 南京航空航天大学 集储能和并离网供电功能的光伏发电系统结构与控制方法
CN203561703U (zh) * 2013-10-29 2014-04-23 国家电网公司 用于光伏并网逆变器低电压穿越测试的电压跌落发生器
DE102013114729B4 (de) * 2013-12-20 2021-09-30 Sma Solar Technology Ag Wechselrichter und Verfahren zum Detektieren eines Phasenausfalls in einem Energieversorgungsnetz
CN106029266B (zh) * 2014-03-28 2021-02-19 东洋铝株式会社 薄片状金属颜料及其制造方法，及其金属组合物和涂布物

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1658465A (zh) * 2005-03-15 2005-08-24 清华大学 兼备无功与谐波补偿功能的光伏并网装置
US20090244938A1 (en) * 2008-03-31 2009-10-01 Sma Solar Technology Ag Switching apparatus for grounding an inverter
CN102738827A (zh) * 2012-06-20 2012-10-17 天津电气传动设计研究所 一种用于三相并网光伏逆变器的低电压穿越控制方法
CN202651808U (zh) * 2012-06-20 2013-01-02 天津电气传动设计研究所 一种电网电压直接前馈的三相并网光伏逆变器系统
CN203466576U (zh) * 2013-08-12 2014-03-05 深圳市合兴加能科技有限公司 一种本质安全型光伏接地系统
CN103647453A (zh) * 2013-12-13 2014-03-19 中南大学 一种基于ccm模式的微逆变器及其控制方法
CN103915856A (zh) * 2014-04-17 2014-07-09 中南大学 一种基站并网-充电光伏微逆变器系统及其控制方法

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108183461A (zh) * 2018-03-05 2018-06-19 温州科宇电器有限公司 一种光伏电站电流方向保护方法及中央控制模块
CN108183461B (zh) * 2018-03-05 2023-09-01 浙江安富新能源科技股份有限公司 一种光伏电站电流方向保护方法及中央控制模块
US20230121559A1 (en) * 2021-10-15 2023-04-20 Caterpillar Inc. Open phase detection
US12066502B2 (en) * 2021-10-15 2024-08-20 Caterpillar Inc. Open phase detection

Also Published As

Publication number Publication date
CN106463968A (zh) 2017-02-22
CA2953834C (en) 2020-07-14
US20170207693A1 (en) 2017-07-20
CA2953834A1 (en) 2016-02-11
CN106463968B (zh) 2019-05-31

Similar Documents

Publication Publication Date Title
WO2016019491A1 (zh) 一种光伏并网逆变器的保护系统及方法
JP7176000B2 (ja) 電力グリッドシステム
EP3024134B1 (en) Parallel inverter system, and shutdown control method and shutdown control device for parallel inverter system
CN104488156B (zh) 故障排除的方法
CN107611937B (zh) 一种直流断路器的过电压保护电路及方法
CN107534296B (zh) 双极dc电力传输结构
CN106208129B (zh) 并联直流电源的接入控制方法及其应用的装置
US9509231B2 (en) Power converter system, damping system, and method of operating a power converter system
TW201438366A (zh) 高可靠的不斷電系統用靜態切換開關電路
CN114977265B (zh) 一种故障检测装置、方法和并网光伏发电系统
JP2018046642A (ja) 直流送電システム
CN104730396A (zh) 用于电力系统的孤岛检测方法及装置
WO2016194898A1 (ja) 直流電流遮断装置
CN108768198A (zh) 一种应用于并网微网的冗余结构容错逆变器及其控制策略
CN107769247B (zh) 一种用于防孤岛检测的rlc负载模拟系统及其控制方法
JP6248716B2 (ja) 故障対処装置、および電源システム
CN103944151B (zh) 一种不接地系统多回平行线路异名相两点接地的保护方法
JP6082667B2 (ja) パワーコンディショナー
CN103208778B (zh) 一种针对大容量储能系统的保护方法
KR101846257B1 (ko) 태양광 발전용 인버터 보호 장치
KR101707264B1 (ko) 인버터
KR101561391B1 (ko) 고전압 직류 송전 시스템
CN110445134A (zh) 一种柔性合环装置
JP5975967B2 (ja) パワーコンディショナ
CN106300294B (zh) 直流电网线路故障恢复方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14899136

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2953834

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 15324101

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14899136

Country of ref document: EP

Kind code of ref document: A1